Orthodontic perspectives of obstructive sleep apnea

OSA is defined as a condition in which there is repetitive partial or complete collapse of the pharynx during sleep. An apnea is defined as an almost complete (at least 90%) cessation of airflow, and hypopnea is defined as a reduction in nasal pressure amplitude of at least 50% and/ or a reduction in thoracoabdominal movement of 50% or more for a minimum of 10 seconds. Often, patients first seek an otorhinolaryngologic (ENT) evaluation rather than presenting to a sleep center. Normal sleep involves air passing through and going directly down to the lungs. With an obstructed airway, the structures in the back of the throat (the tongue, the tonsils, and/or adenoids) occlude the airway due to an inadequate motor tone of the tongue and/or airway dilator muscles, and thus, prevent the air from passing. The aetiology is multifactorial, and the main risk factors in children include adenotonsillar hypertrophy, obesity, neuromuscular disorders and craniofacial anomalies. Adenotonsillar hypertrophy is the most commonly reported aetiological factor. Therefore, the treatment of choice for paediatric OSA is adenotonsillectomy. In adulthood, the use of oral appliances is a treatment option in the management of OSA